Patrick Golder writes>
>From what I've read, Grade 5 is
>considered the minimum strength for automotive use, though other grades
>are used depending on the application. The key seems to be to use a
>fastener that's at least as strong as the one the manufacturer originally
>used.
Not exactly. People have a habit of saying that Grade 8 is "better" than
Grade 5. Not so. Grade 8 lets you get things tighter than Grade 5. This is
good for cylinder heads and wheel studs, where the work is actually done by the
compression of the parts together. In shear applications where you can expect
shock forces, Grade 8 bolts will often break because they are too hard. I
would always favor Grade 5 in roll bars and suspension bushings.
Phil Ethier, THE RIGHT LINE, 672 Orleans Street, Saint Paul, MN 55107-2676
h (612) 224-3105 w (612) 298-5324 phile@pwcs.stpaul.gov
"The workingman's GT-40" - Anthony Colin Bruce Chapman
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